What Oda specialized is world building he is top notch at that, there is a big world with many people clashing or allying
On that front few of the usual popular shounen can compete, their world too small and narrow.
Story wise is okay to good, he struggles with pace one of his biggest weakness and bloating arcs with new characters
But Oda is a master at emotional moments, when he wants you to feel for something he mostly achieves it. His plot also comes for a long time foreshadowing of 200+ chapter ago setup.
Overall a suck ass weakness when he is moving the story at glacial pace on a weekly shounen, but a very interesting world, with many likeable character outside of the main cast.
I think One Piece deserves top 5, but if not definitely top 10